Event-by-event fluctuations in heavy ion collisions

We discuss the physics underlying event-by-event fluctuations in relativistic heavy ion collisions. We will argue that the fluctuations of the ratio of positively over negatively charged particles may serve as a unique signature for the Quark Gluon Plasma.Comment: Contribution to the Proceedings of the International Workshop XXX on Gross Properties of Nuclei and Nuclear Excitations, Hirschegg, Jan. 2002 and to the Proceedings of the Krakow Epiphany Conference, Krakow, Jan. 200

Gravitational radiation from elastic particle scattering in models with extra dimensions

In this paper we derive a formula for the energy loss due to elastic N to N particle scattering in models with extra dimensions that are compactified on a radius R. In contrast to a previous derivation we also calculate additional terms that are suppressed by factors of frequency over compactification radius. In the limit of a large compactification radius R those terms vanish and the standard result for the non compactified case is recovered.Comment: 17 page

Exciton-Population Inversion and Terahertz Gain in Resonantly Excited Semiconductors

The build-up of exciton populations in resonantly laser excited semiconductors is studied microscopically. For excitation at the $2s$-exciton resonance, it is shown that polarization with a strict $s$-type radial symmetry can be efficiently converted into an incoherent $p$-type population. As a consequence, inversion between the $2p$ and $1s$ exciton states can be obtained leading to the appearance of significant terahertz gain.Comment: 4 pages, 3 figure

Water resources assessment and management in drylands

Drylands regions of the world face difficult issues in maintaining water resources to meet current demands which will intensify in the future with population increases, infrastructure development, increased agricultural water demands, and climate change impacts on the hydrologic system. New water resources evaluation and management methods will be needed to assure that water resources in drylands are optimally managed in a sustainable manner. Development of water management and conservation methods is a multi-disciplinary endeavor. Scientists and engineers must collaborate and cooperate with water managers, planners, and politicians to successfully adopt new strategies to manage water not only for humans, but to maintain all aspects of the environment. This particularly applies to drylands regions where resources are already limited and conflicts over water are occurring. Every aspect of the hydrologic cycle needs to be assessed to be able to quantify the available water resources, to monitor natural and anthropogenic changes, and to develop flexible policies and management strategies that can change as conditions dictate. Optimal, sustainable water management is achieved by cooperation and not conflict, thereby necessitating the need for high quality scientific research and input into the processhttp://www.mdpi.com/2073-4441/8/6/239Published versio

Computer aided processing using laser measurements

The challenge exists of processing the STS and its cargo through KSC facilities in the most timely and cost effective manner possible. To do this a 3-D computer graphics data base was established into which was entered the STS, payloads, and KSC facilities. The facility drawing data are enhanced by laser theodolite measurements into an as-built configuration. Elements of the data base were combined to study orbiter/facility interfaces payload/facility access problems and design/arrangement of various GSE to support processing requirements. With timely analysis/design utilizing the 3-D computer graphics system, costly delays can be avoided. Better methodology can be analyzed to determine procedures for cost avoidance